Sacellum of Nordrassil

I've been fielding quite a few questions lately concerning armor values and itemization. I'll try to address some of the main questions here. While this post is in the Paladin section, this information applies to all tanks.

Basics:

- Armor reduces the physical damage you take by a certain percentage. This amount changes basd on the level of the mob hitting you, regardless of your level. The damage reduction value displayed on your character sheet indicates the damage reduction applied to a hit from an equal level attacker. Thus, against higher level and boss mobs you will actually have less damage reduction than what is displayed.

- The armor cap is 75%. At this point, you take 1/4 the damage compared to an unarmored state. Note that the armor it takes to get to 75% damage reduction against a level 83 mob is more than the armor it takes to get 75% displayed on your character sheet.

- Damage reduction due to armor is passive and static.

Maths:

Armor = 2*Agiliity + [Armor from gear] + [Magic armor]

Magic armor includes buffs, enchants (gear armor kits), scrolls, etc. Talents do not boost this value.

Damage Reduction = (Armor/((467.5 * Enemy Level) + Armor - 22167.5)) * 100

For a level 80 mob (and your character sheet), this simplifies to:
Damage Reduction = (Armor/(Armor+15232.5))*100

For a level 83 boss mob, this simplifies to:
Damage Reduction = (Armor/(Armor+16635))*100

What does this mean? Let's break down the fomula a little bit. We'll use the level 80 formula so it matches up with your character sheet values at home.

For X amount of armor, X/(X+15232.5) = proportion of damage reduction. When X is equal to 15232.5, damage reduction (DR) = .5, 50%, or 1/2. This is an important benchmark, as this is the point where you are able to take double the damage compared to an unarmored state.

Note that when X is equal to 2*15232.5, DR = .667, 66.7%, or 2/3. At this point you can take triple the damage compared to an unarmored state.

Extrapolate and you can find that the armor cap for lvl 80 mobs is 3*15232.5 or 45697.5.

"But Pentheus, if it takes 15000+ armor to get from 50% to 66%, and another 15000+ to get to 75% from 66%, doesn't that constitute diminishing returns? And if so, at what point do I stop stacking armor?"

While the initial example is true, the conclusion is not. Yes, every infintesimal % of damage reduction added has a higher cost in armor value than the previous. In that sense, there is diminishing returns when calculating from the baseline of an unarmored state. However, in a practical setting, your baseline is not an unarmored state but rather somewhere in the realm of 50% to 75%, depending on your class and gear.

For example, imagine someone at 60% DR. This hypothetical tank adds enough armor for 1% to get to 61% DR. While at first glance it appears to be a 1% decrease in damage taken, a closer inspection tells you it is more. At 60% DR our imaginary tank is taking 40% of the hit as damage. After adding the armor to get to 61% DR, our tank is now taking 39% of the hit as damage. The difference here is 39/40, or 2.5%, much larger than the 1% initially suggested.

Notice that as your DR rises, each subsequent % is worth more than the previous in terms of relative DR. We'll look at the exremes for proof:

Imagine going from 0% DR to 1%. Damage taken changes from 100% to 99%, so this is exactly a 1% decrease in damage taken. Now imagine going from 90% to 91%. Damage taken shifts from 10% to 9%, a 10% reduction in damage taken.

To recap: Yes, it takes more and more armor to increase your DR by 1% as your armor value grows. At the same time, each 1% of DR is worth more than the last 1% as your armor value grows. We can do that math for this next time, but for today just know that within the practical realm (60%-75%), these two opposing curves just about cancel each other out. This means that for the purpose of itemization choices, you can treat gains from armor as basically linear.

thanks for the post, good to know. Question though, do you know how stamina and armor scale in EH? If you could post some sort of conversion that'd be great.

EH is a derivative of your HP, armor, avoidance, passive mitigation, and damage reduction talents. It is how much health you would have if you had no armor or damage reduction at all. Calculations generally pertain to physical damage.

Here are some imaginary numbers. We'll keep them pretty round for the sake of easy calculation.

40,000 hp

With no avoidance, talents, armor, or block: EH = 40,000

Let's add some modest avoidance, say 30% combined dodge and parry. Only 70% of attacks land, so it will take 100/70, or 142.9% the attacks in the baseline situation to reach tank death.

With 30% avoidance and no talents, armor, or block: EH = HP * 100/(100-avoidance%) = 57142.

With 6% DR from Improved Righteous Fury (of course this isn't the only talent that provides DR. Adjust your formula to fit your reality):
Each hit does 6% less. Again, this is pretty simple. It takes 100/94 of the baseline number of attacks, or 106.4%, to reach tank death.

With 30% avoidance, 6% DR from talents, and no armor or block: EH = HP * 100/(100-avoidance%) * 100/(100-DR%) = 60790

Armor

This is probably the most simple conversion. Let's say armor value provides 65% damage reduction, meaning incoming hits are only at 35% of the original potency. 100/35 = 285.7%.

With 30% avoidance, 6% DR from talents, 65% DR from armor, and no block: EH = HP * 100/(100-avoidance%) * 100/(100-DR%) * 100/(100-ArmorDR%) = 173686

Block is a bit more dynamic, so we will look at the baseline values for calculation. Block% tends to be pretty low these days, so let's say 10% for a paladin, with a 2000 pt BV. Assuming 100% Holy Shield uptime, this rises to 40%. So 40% of hits are reduced by 2000 pts. What makes this variable in terms of EH is the spectrum of hits you will be taking. This mitigation is obviously worth more if you are taking weak hits and less if they are big hits. Again, it helps to imagine the extremes. 2000 pt hits will put this in the realm of avoidance, as far as % of the hit mitigated. 50000 pt hits will cause this to mean much less. Here is the caveat: Block is the last part of the damage equation, meaning all other avoidance/mitigation/damage reduction are affected before applying your block value. This is what keeps block value from being trivial.

Assume a 50,000 pt swing (which is pretty normal). Apply DR noted above (6% and 65%) and we get 50,000*[1-.06]*[1-.65] = 30550. Subtract the block value from this and we get 28550. Thus, the number of total swings multiplied by the block % is the number of attacks that are reduced by 2000/30550 = 6.5%. 40% BR% * 6.5% BV = 2.6% BDR

With 30% avoidance, 6% DR from talents, 65% DR from armor, and 40% block and 2000 BV: EH = HP * 100/(100-avoidance%) * 100/(100-DR%) * 100/(100-ArmorDR%) * 100/(100-([block value/((enemy swing value*[talent DR]*[armor DR])-block value)] * block %)) = 178322.

I'm sure that equation can be simplified, but I'll leave that to you. Feel free to point out any errors, I went through this pretty quickly.

(Pentheus first post + Pentheus second post)/simplicity= Tanks take less damage with more armor. Tanks live longer. We win.